Motorcycle transmissions occasionally include a transmission case and a fill spout coupled to the transmission case. The fill spout communicates with an internal passageway in the transmission case leading to a sump containing lubricant. To add lubricant to the sump, the lubricant is poured into the fill spout. From the fill spout, the lubricant flows down the internal passageway and collects in the sump.
When fill spouts are constructed of separate components or assemblies they are fastened to transmission cases by fasteners to achieve a consistent clamping force around the periphery of a flat gasket positioned between the fill spout and the transmission case. Also, fill spouts in motorcycle transmissions are occasionally integrated into transmission case covers coupled to upper portions of transmission cases.